The workers voted 500 to 16 before and after Saturday's home game against the Atlanta Braves to give Unite Here Local 2 representatives the bargaining tool, said Nischit Hegde, a spokeswoman for the union.

Workers will not immediately strike, but instead wait to see how South Carolina concession management firm Centerplate responds to the vote, Hegde said.

"People are very serious about what they need, and they want to be taken seriously, and I think a 97 percent authorization vote displays how serious they are," Hegde said.

Roughly 750 union-represented concession workers at the ballpark - from cashiers and cooks to suite attendants and food hawkers - have been working without a contract for three years.

Union leaders called for the strike vote after negotiations bogged down over economic issues and management's refusal to guarantee that a contract would be enforced if the Giants replaced Centerplate as their concessionaire.

Centerplate and the union are scheduled to continue their talks this week.

"We see this as an unfortunate decision today that was encouraged by the unions," said Centerplate spokeswoman Gina Antonini. "This as a very unnecessary step given that there are active negotiations going on."

Should the workers eventually decide to walk out, the stadium concessions would be staffed by management and other employees, Antonini said.